Morphology of two eastern Pacific eelpouts (Pisces, Zoarcidae, Lycodes) in connection with features of distribution of species with a double lateral line

Abstract

Morphology of two endemic eastern Pacific species of eelpouts—blackbelly Lycodes pacificus Collett, 1879 and bigfin L. cortezianus Gilbert, 1891—were studied. It was shown that these two species are characterized by unreduced seismosensory system of the head and belong to a species group with a double lateral line. It was suggested that the ancestral form of this species group could have possibly dispersed in the Atlantic Ocean through the Panama Canal in the pre-Pleistocene time. It is likely that the antitropical distribution of the Newfoundland eelpout L. terranovae is related this event.